Tomato, lentil and tamarind soup, or thakkali rasam, is a thin lentil soup with tamarind and chopped tomatoes, a traditional spice powder  and a simple seasoning of tempered oil with mustard seeds and curry leaves. The consistency of rasam should be thin, but not watery.

Rasam is served as a second course in a traditional meal, but for a simple meal, the soup is served over the top of plain white rice.  If you want a thicker, more robust soup, then look at some of the sambar recipes in this book.

Rasam should have some bite, but not be exceedingly hot. You should be able to taste the sourness of the tamarind, the flavour of the tomatoes, then the subtlety of the spices. This spice mix is included in this collection – it is called rasam masala.

As you would expect of a common, simple family dish, the preparation is easy. Simply put everything in a pressure cooker for 15 minutes, mash then add the tempered oil and serve. What could be easier? If you do not use a pressure cooker, it is easily done on the stovetop, but may take upwards of 45 minutes to simmer the tomato and lentils.

Despite this popularity and its place in traditional cuisine, I have never seen this on the menu at local restaurants. Just why, I don’t know.

the recipe

prep 10 minutes
cook 20 minutes
soak 12 hours
total 30 minutes
servings 6 servings
calories 136 kcal


for tempering

to serve

  • 1 cup coriander leaves


  1. Wash toor dal well, then place in bowl and cover with water. Allow to soak overnight.

  2. Put toor dal and water into the pressure cooker and bring to a gentle boil, A foam will develop from the lentils, which you should remove with a spoon and discard. Continue this process for around 3-4 minutes until no more foam is produced.
  3. Reserve ½ cup of the chopped tomatoes and set aside.
  4. Add tomatoes, rasam masala, salt, coriander stems, tamarind, jaggery, turmeric and asafoetida. Bring to the boil, and pressure cook for 10 minutes. Release pressure quickly when done.
  5. Using a potato masher or stick blender, mash the tomatoes and lentils. Keep on a low simmer. Do not boil the rasam or it will lose flavour.
  6. In a small pan heat the mustard oil and add the mustard and cumin seeds. When the mustard seeds pop, add the curry leaves and reserved chopped tomato. Fry for about one minute then stir into the rasam.
  7. Simmer for another minute, stirring continuously.
  8. Serve, and garnish generously with coriander leaves.


  • Remove the foam from the boiling lentils to prevent the pressure cooker valve from becoming clogged.
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